History Main / ThisIsYourBrainOnEvil

* ''ComicBook/SonicTheHedgehogArchieComics'' delved a little into this with the Chaos Emeralds. Knuckles' ancestor Dimitri, who would later become the power-mad Enerjak, got hit with the "withdrawal" symptoms of this trope once his Enerjak powers were removed; rendered unchanged by his powers for centuries, their sudden absence quickly reduced him to a frail old man on the verge of death, forced to live on cybernetic means for the rest of his life (and in one possible future, being reduced to a head in a jar).
** Similarly, in a (now non-{{canon}}) future, Knuckles gets juiced up on Chaos power and goes mad, [[AGodAmI attempting to reshape his world as he sees fit]]. He was stopped by Sonic and an alien device, but it robbed him of an eye and all but irreversibly annihilated his relationship with the hedgehog. Note that canonically, he's already been pumped up with Chaos energy once, and while he didn't go insane or anything, he still died (he got better, though). This actually sort of happened in one arc with Knuckles being taken over by the Enerjak power - however, it ended on a better note with Sonic forgiving him, though Knuckles still feels bad about it.

* In the ''Emerald Twilight'' arc of ''Franchise/GreenLantern'', Hal Jordan starts out slightly unbalanced with grief over the freaking ''demolition of his home city'' and after a minor nervous breakdown, charges out towards Oa to call out the guardians for their long-running history of being selfish assholes. However, [[JumpingOffTheSlipperySlope he then starts robbing and killing all the other Lanterns who get in his way]], and goes from "unbalanced" to "totally batshit insane" over the space of 22 pages. At the time of publication, it was more a DespairEventHorizon, but it was then {{retcon}}ned that Hal had actually been infected by a fear-feeding GiantSpaceFleaFromNowhere, meaning Hal apparently lost his mind as soon as he got corrupted.

[[folder:Fanfictions]]

* [[Literature/LeftBehind Nicolae Carpathia]] is ''made'' of this trope.

* Most characters in ''Manga/SoulEater'' who go through a FaceHeelTurn starts to suffer from quick deterioration of their mental faculties soon after, which is not at all surprising, considering that a FaceHeelTurn in this series usually means giving in to [[TheCorruption insanity]]. Examples include [[spoiler: Franken Stein]] in the anime; [[spoiler: Justin Law and Crona]] in the manga; and, obviously, [[BigBad Kishin Asura]] in both.

* During the Alien Costume StoryArc, Franchise/SpiderMan becomes addicted to the power and freedom the ComicBook/{{Venom}} symbiote gave him... until he learned that it exacerbated his aggressive tendencies and would've absorbed him into itself in the long run. Peter Parker managed to "quit" the symbiote, but his successor, Eddie Brock, wasn't so lucky. Note that this wasn't actually a part of the original comic book version, [[LostInImitation but has appeared in all the adaptations]]. Brock '''seems''' to be better, now. At the moment. Sort of. Meanwhile, under the symbiote's influence, Mac Gargan has crawled up the food chain of evil, in more ways than one. A few hosts later, Eddie is currently reunited with Venom, although over the years the symbiote stopped being a bad influence and became much more benevolent.

* The Apple of Discord has this effect in ''Series/TheLibrarians''. Anyone who touches it becomes the worst version of themself, with Cassandra Cillian in particular becoming rather murderous. Ezekiel Jones is the only person immune to its effects, as he is already the worst possible version of himself.

* ''Series/Highlander'' had Duncan suffer from a Dark Quickening, which turned him evil ("Something Wicked" S413). He got better ("Deliverance" S414).

* In ''Film/SpiderMan3'', the Venom symbiote has this effect on its hosts. Peter is eventually able to [[FightingFromTheInside fight off its influence]] after he has an [[MyGodWhatHaveIDone epiphany]] on what it's turning him into, while Eddie Brock eventually decides that he ''[[EvilFeelsGood likes]]'' being evil.

* ''Series/Highlander'' had Duncan suffer from a Dark Quickening, which turned him evil ("Something Wicked" S413). He got better ("Deliverance" S414).

* The boy who would become Wrath in the 2003 anime version of ''Anime/FullmetalAlchemist'' was a sweet, shy, and innocent young child who was suffering from a nasty case of amnesia when he was first introduced to the audience. [[AxCrazy Then Envy has him eat unfinished Philosopher's Stones...]]

-->'''Pumpkin''' Forget it, it's too risky. I'm through doing that shit.\\

->'''Pumpkin''' Forget it, it's too risky. I'm through doing that shit.\\

* In ''Film/SpiderMan2'', Otto Octavius has an epiphany after getting knocked around by Peter, realizing that his arms have been manipulating ''him'', and urging him to evil. Sadly, he was surgically fused with them and [[NotQuiteDead may have "died"]] because RedemptionEqualsDeath. Also the Venom suit in ''Film/SpiderMan3''.